This invention relates to control circuits for electrical appliances. More specifically, the invention relates to switches for use with power tools, such as electric drills, jigsaws and the like. For such applications it is necessary to provide a switch which is highly reliable, durable and yet compact and low in cost. For heavy duty power tools, such switches must handle high currents (on the order of four to six amps or more) during operation. Accordingly, arcing is a problem because of these high current loads. Thus, the contacts must be designed to minimize arcing but yet have sufficient surface area to insure good electrical contact over extended service periods. These requirements are difficult to achieve in view of the necessity for manufacturing such a switch as inexpensively as possible.
In many applications it is additionally desirable that the switch include circuit means for controlling the speed of the tool operation as, for example, the revolutions per minute of a drill.